Modern computers typically comprise a central processing unit ("CPU") interconnected to dynamic memory, peripherals, and read only memory. Upon initialization of such a computer, instructions are loaded from the read only memory ("ROM") which, in turn, direct the computer to execute a set of initial program load instructions. These instructions typically direct the processor to access an initial peripheral in order to properly load further operating instructions. The ROM may also direct the computer to display information in response to such an initial program load sequence on a second peripheral.
In a personal computer for example, a ROM basic input/output system ("BIOS") directs a central processor ("CPU") upon initialization to display certain status information on a display peripheral such as a monitor and to query a local peripheral such as a keyboard for instructions. Thereafter, the BIOS instructs the CPU to perform an initial program load sequence to load a program from another peripheral such as a disc drive, into dynamic memory. During this initial program load further display information is presented to the display peripheral and the initial program load may be modified or aborted using the keyboard input peripheral.
In other computer systems such as in existing UNIX work stations or network servers, ROM directs a CPU and hence the computer to obtain further initial program load parameters from a terminal, such as a VT100 console, which is interconnected to the UNIX computer by a console port. Upon initialization, a system administrator may instruct a work station by a terminal connected to the console port to load the required UNIX operating system from another peripheral. During loading, any display and status messages are presented to the console port, which in turn directs the terminal to display such information. After loading of the operating system is complete, the console port remains active, under control of a UNIX process, allowing an administrator to provide administration commands to the computer and operating system at any time. Thus, the console port actually acts as an administration port, providing administrative access to the computer. It is the first point of access and provides administration access at all times in most UNIX based computers.
In modern computers, one of the peripherals interacting with the CPU is a network input/output ("I/O") interface. The network I/O interface provides the computer with a data communications link to other computers and peripherals in order to allow for the exchange of data. At present, such I/O interfaces are often Ethernet interfaces to allow networked computers to communicate using an Ethernet. This network I/O interface however, is distinct from the administration port described above. Indeed, it is known to allow the loading of an operating system via this network I/O interface after proper initial program load instructions and parameters have been obtained through the administration port. Thus, for example, in a UNIX environment, it may be possible to direct a UNIX work station to load the UNIX operating system from another network server through the network interface. Upon initialization of a UNIX computer system, the system administrator may use a terminal, connected to the console port in order to direct the computer to load the operating system through the network I/O interface.
This design is premised largely on the assumption that administrators have direct physical access to the computer in order to access the administration port. In a network environment however, such physical access is often not guaranteed and indeed often not available. As the console port is often the first and last port of access for a computer, remote access to the administration port, separate from network access to the computer has been suggested.
One solution has involved connecting the console ports of a plurality of UNIX computers to a terminal server. A terminal server functions as a concentrator and comprises a plurality of inputs for a plurality of console ports and a single output. The output may be a single console port output or a network output. A system administrator may connect a single terminal to the output side of a terminal server device. The inputs of the terminal server may be connected to the individual console ports of a plurality of computers each having such a console port. Thus, a system administrator can centralize administration tasks at a single location by concentrating the console ports for multiple administered computers.
While reducing the number of terminals required to be connected to a plurality of computers, this solution still requires two separate physical external connections for each computer connected to a data network: the network I/O interface and the administration port interface. Moreover, this solution requires individual physical connections between each computer and the terminal server and thus suggests physical proximity of the administration facilities and administrator to the plurality of computers whose console ports have been concentrated by the terminal server. Additionally, without further connectivity, the console ports may only be accessed at a single physical location.
A further solution may be found in certain modern telephony systems. In such systems, for example, a plurality of proximate UNIX computers are networked to each other by a local area network ("LAN"). Each computer comprises a network I/O interface connecting the networked computers to each other. Typically, the computers use a known datalink and network protocol, adhering to the IEEE 802 standard, to transport data along the LAN. The LAN is often an Ethernet. Data is exchanged by a known protocol such as IPX or TCP/IP. This LAN is used to exchange data required for call processing. Additionally, the computers are interconnected by a separate physical local control or administration network. As each of the computers is further equipped with a console port, the plurality of console ports are interconnected by a console port network. The console port network allows a single central computer (known as an operations controller, or "OC") in the network to access the console ports of the remaining computers (known as service computers, or "SC"s). The console port of the OC is connected to a physical interface, such as a terminal having a keyboard and display. Thus, the OC is accessed by this physical interface and can pass initial program load and administration instructions to the SCs by the console port network. For example, the operating system or other initial program loading information for the SCs on the network may be loaded via the console port network. As is apparent, this configuration requires two physical sets of network connections: a console port network, and a data exchange network, as well as two physical sets of network cabling.
In fact, often such telephony systems incorporate a third network used for equipment monitoring (`telemetry`) of operating conditions of each of the computers, as more particularly described in U.S. Pat. No. 5,594,893. This third telemetry network, typically comprises a plurality of local serial links ("LSL"s), interconnecting a plurality of SCs, housed in a single shelf to a frame supervisory controller ("FSC"), also housed in that shelf. A remote serial link ("RSL") connects an OC, typically housed in a separate shelf to the FSC of the SCs. The LSL are interconnected to monitoring equipment that monitors such conditions, as power converter status, circuit breaker status, temperature and the like for each of the networked computers. Data representing the monitored conditions which is periodically transferred via the LSLs, FSC and RSL to the OC. In response to sensed conditions, the OC may initiate graceful shutdowns of the SCs, or otherwise report or react to sensed conditions. As will be appreciated the use of such a telemetry network introduces the use of a third physical network with a third set of network cabling.
It is an object of the present invention to provide an improved computer network adaptor allowing an improved network architecture for data exchange and administration of a plurality of network computers.